George Weasley

Talking about George Weasley without his twin Fred is like trying to explain yin without yang, doppels without gangers...well actually no it's not, they're both infuriating but mostly harmless. So I guess the dualism thing doesn't work. Too bad... I was hoping to fit in something completely unrelated about Ahura Mazda without Angra Mainyu. Basically they're the tweedles except weirder and with red hair.

Spoiler Alert: The Weasley twins, being characters in a book, are involved in the story. Any discussion of characters involved in a story may entail additional and unwanted information about plot developments (colloquially known as spoilers.) This statement has not been approved by the FDA.

For most of the books they basically come as a set and neither has a very distinct personality, though as a team they're very uhh.. colorful. Like a few other famousliterarytwins they display a natural talent for getting into and creating trouble, though they are arguably the best at it. They often move the story along, for instance in the third year giving Harry a magical map shows all of Hogwarts (including the seriously secret passages that Filch doesn't know about)and that conveniently labels all approaching authority figures... and just happened to have been created by his father's band of friends. They also sell Peruvian Instant Darkness powder to Draco Malfoy in their joke shop Weasley's Wizard Wheezes -- which they founded with the money that Harry won in the Triwizard Tournament and donated to their dream -- their mother found this acceptable as soon as the wizarding world began falling apart, the entire family became estranged to Percy (don't worry though it all works out in the end) and they began raking in Galleons.
They provide comic relief througout the books, e.g. accusing Harry (then 12) of being a "seriously dark evil wizard," and filling the Gryffindor common room with fainting first years.
...and of course after 6 years of attending Hogwarts, torturing Filch, trying to give Mcgonagall heart attacks and generally investigating whatever happened to be forbidden and intriguing, they made a grand exit in book 5 which contributed to the befuddlement and the eventual downfall of the hated Dolores Umbridge. Ooops, should I have warned you about spoilers? Anyhow since we're doing that nasty ruining the surprise stuff.. they join the order of the phoenix, Fred gets killed and the George marries Angelina Johnson who he had early asked to the Yule Ball on an impulse (we found this out in that really sucky epilogue.) So half of them live happily ever after.
The twins are friends with Lee Jordan from the very first book, who while not quite as devoted to making mischief is a very close friend and eventually becomes part of the Order of the Phoenix himself. And their brother is a werewolf which because of transitivity means that their sister-in-law is a veela.